INCREASED MORTALITY FROM CHRONIC LIVER-DISEASE AND CIRRHOSIS 13 YEARSAFTER THE TAIWAN YUCHENG (OIL DISEASE) INCIDENT

In 1979, a mass poisoning involving some 2,000 persons occurred in cen tral Taiwan from cooking oil contaminated by polychlorinated biphenyls (PCBs) and their hear-degraded byproducts, including polychlorinated dibenzofurans (PCDFs). The responsible health department register-ed c ases for clinical purposes between 1979 and 1983. The exposed persons are referred to as the ''yucheng''(oil disease) cohort. PCBs and PCDFs are toxic chemicals widely dispersed in the environment and in human tissue, which persist long after exposure. The consequences of exposur e to these agents are not well understood. We traced the cohort throug h December 31, 1991, and compared overall and cause-specific mortality of 1,837 ''yucheng'' subjects with age, gender and calendar time-spec ific mortality rates for the Taiwan general population. Eighty-three d eaths were identified from 23,404 observed person-years. Evert though the overall standardized mortality ratio (SMR) was O.8 (95% confidence interval (Cl) 0.7-1.0), there was a substantial elevation in the mort ality rate for chronic liver disease and cirrhosis (10 deaths, SMR = 2 .7, 95% Cl = 1.3-4.9). Mortality from malignant neoplasms and other ca uses was not significantly different from that of the Taiwan populatio n. PCB/PCDF exposure appears to promote the development of severe live r disease, perhaps in combination with known risk factors such as infe ction with hepatitis B virus. Further follow-up of this young cohort i s necessary to see if the consequences include hepatic cancer. (C) 199 7 Wiley-Liss, Inc.